There is a way from App store to send an email containing the information about an app. However there is no way of just copying the app URL in case I want to send that URL on other services like Line or whatever. Or is there?
At least in the App Store app in iOS 6 you can copy the link by tapping on the Sharing icon.
If this is not available in earlier versions there is always the option of sending a mail to oneself and taking the link from there.